1. Field of the Invention
The present invention is directed to aluminum receptacles and, more particularly, to aluminum receptacles having a threaded neck for receiving a cap.
2. Description of the Background
It is known in the art to form drawn, or drawn and ironed, cans from aluminum and steel for use in the packaging of beer, soft drinks, oil, and other liquids. Most metal cans for beer and beverages are adapted to be closed with relatively flat lids or ends which are secured on the cans by double seaming or a similar process. The lids may have tear strips formed in them and pull tabs attached to the tear strips to facilitate access to the tear strips to thereby provide an opening in the lid.
Not all aluminum containers have flat tops. It is known in the art to use a series of necking dies on an aluminum container to form a neck on one end of the container. Threads may then be formed in the neck portion of the container by positioning first and second thread rolling tools adjacent to inside and outside surfaces, respectively, of the neck and rotatably moving the tools against the surface. Threaded aluminum containers have typically been made from relatively thick metal, i.e., at least 0.020 inches thick. The material is typically pure aluminum (99.5-99.8% aluminum) which is relatively soft and permits the forming of threads in the neck.
The insides of aluminum containers are very often provided with a coating which prevents interaction between the raw aluminum and the contents of the container. The process of forming threads on the neck portion of the container may crack and/or dislodge portions of the coating thereby allowing the contents of the container to come into contact with raw aluminum. Furthermore, a coating which is cracked or otherwise damaged may work loose after the container is filled thereby contaminating the contents of the container.
An improvement over forming the threads directly in the aluminum container is to secure a sleeve of plastic or other material around the neck of the aluminum container. Examples of the use of such a sleeve can be found in U.S. Pat. No. 5,713,235 entitled “Method and Apparatus for Die Necking a Metal Container,” U.S. Pat. No. 6,010,026 entitled “Assembly of Aluminum Can and Threaded Sleeve,” U.S. Pat. No. 5,718,352 entitled “Threaded Aluminum Cans and Methods of Manufacture,” U.S. Pat. No. 5,778,723 entitled “Method and Apparatus for Necking a Metal Container and Resultant Container,” U.S. Pat. No. 6,010,028 entitled “Lightweight Reclosable Can with Attached Threaded Pour Spout and Methods of Manufacture,” and U.S. Pat. No. 5,822,843 entitled “Method of Making Bottle-Shaped Metal Cans.” Very often, to prevent rotation of the sleeve on the container, small dents, ribs, slots or the like are provided on the container and/or the sleeve. The sleeve can also be adhesively bonded to the container to prevent relative rotation. However, forming of dents, ribs, slots, or the like in the container may damage the protective coating on the inside of the container. Therefore, the need exits for a method for securing a threaded sleeve to the neck of an aluminum container and the improved container resulting therefrom.